/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.  You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 ******************************************************************************/
package com.bstek.urule.runtime.rete;

import com.bstek.urule.model.rule.lhs.BaseCriteria;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * @author Jacky.gao
 * @since 2015年1月8日
 */
public class AndActivity extends JoinActivity {
    private List<Path> fromPaths = new ArrayList<Path>();
    private boolean pass;
    private FactTracker currentTracker;
    private Map<Activity, List<Map<String, Object>>> toActivityMap = new HashMap<Activity, List<Map<String, Object>>>();

    private static List<Map<String, Object>> buildVariableMaps(List<Map<String, Object>> list1, List<Map<String, Object>> list2) {
        List<Map<String, Object>> resultList = new ArrayList<Map<String, Object>>();
        for (Map<String, Object> map1 : list1) {
            if (list2.size() == 0) {
                resultList.add(map1);
            } else {
                for (Map<String, Object> map2 : list2) {
                    Map<String, Object> newMap = new HashMap<String, Object>();
                    newMap.putAll(map1);
                    newMap.putAll(map2);
                    resultList.add(newMap);
                }
            }
        }
        return resultList;
    }

    public Collection<FactTracker> enter(EvaluationContext context, Object obj, FactTracker tracker, Map<String, Object> variableMap) {
        Activity prevActivity = context.getPrevActivity();
        if (prevActivity != null) {
            if (toActivityMap.containsKey(prevActivity)) {
                List<Map<String, Object>> variableList = toActivityMap.get(prevActivity);
                if (pass) {
                    variableList.clear();
                }
                variableList.add(variableMap);
            } else {
                List<Map<String, Object>> variableList = new ArrayList<Map<String, Object>>();
                variableList.add(variableMap);
                toActivityMap.put(prevActivity, variableList);
            }
        }
        if (currentTracker != null) {
            Map<Object, List<BaseCriteria>> map = tracker.getObjectCriteriaMap();
            Map<Object, List<BaseCriteria>> currentMap = currentTracker.getObjectCriteriaMap();
            for (Object key : currentMap.keySet()) {
                if (map.containsKey(key)) {
                    continue;
                }
                map.put(key, currentMap.get(key));
            }
        }
        currentTracker = tracker;
        if (isAllPassed()) {
            context.setPrevActivity(this);
            pass = true;
            List<FactTracker> allTrackers = new ArrayList<FactTracker>();
            List<Map<String, Object>> list = buildPathVariableMaps();
            for (Map<String, Object> varMap : list) {
                List<FactTracker> trackers = visitPahs(context, obj, tracker, varMap);
                if (trackers != null && trackers.size() > 0) {
                    allTrackers.addAll(trackers);
                }
            }
            return allTrackers;
        }
        return null;
    }

    private boolean isAllPassed() {
        boolean passed = true;
        for (Path path : fromPaths) {
            if (!path.isPassed()) {
                passed = false;
                break;
            }
        }
        return passed;
    }

    public void addFromPath(Path fromPath) {
        fromPaths.add(fromPath);
    }

    private List<Map<String, Object>> buildPathVariableMaps() {
        List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
        Iterator<List<Map<String, Object>>> iter = toActivityMap.values().iterator();
        while (iter.hasNext()) {
            List<Map<String, Object>> list1 = iter.next();
            result = buildVariableMaps(list1, result);
        }
        return result;
    }

    @Override
    public boolean orNodeIsPassed() {
        return false;
    }

    @Override
    public void reset() {
        toActivityMap.clear();
        pass = false;
        currentTracker = null;
    }
}
